/*

 * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package javax.sql.rowset.serial;

import java.sql.*;

import java.io.*;

import java.util.Map;

import java.net.URL;

import java.util.Arrays;

/**

 * A serialized version of an <code>Array</code>

 * object, which is the mapping in the Java programming language of an SQL

 * <code>ARRAY</code> value.

 * <P>

 * The <code>SerialArray</code> class provides a constructor for creating

 * a <code>SerialArray</code> instance from an <code>Array</code> object,

 * methods for getting the base type and the SQL name for the base type, and

 * methods for copying all or part of a <code>SerialArray</code> object.

 * <P>

 *

 * Note: In order for this class to function correctly, a connection to the

 * data source

 * must be available in order for the SQL <code>Array</code> object to be

 * materialized (have all of its elements brought to the client server)

 * if necessary. At this time, logical pointers to the data in the data source,

 * such as locators, are not currently supported.

 *

 * <h3> Thread safety </h3>

 *

 * A SerialArray is not safe for use by multiple concurrent threads.  If a

 * SerialArray is to be used by more than one thread then access to the

 * SerialArray should be controlled by appropriate synchronization.

 *

 * @since 1.5

 */

public class SerialArray implements Array, Serializable, Cloneable {

    /**

     * A serialized array in which each element is an <code>Object</code>

     * in the Java programming language that represents an element

     * in the SQL <code>ARRAY</code> value.

     * @serial

     */

    private Object[] elements;

    /**

     * The SQL type of the elements in this <code>SerialArray</code> object.  The

     * type is expressed as one of the constants from the class

     * <code>java.sql.Types</code>.

     * @serial

     */

    private int baseType;

    /**

     * The type name used by the DBMS for the elements in the SQL <code>ARRAY</code>

     * value that this <code>SerialArray</code> object represents.

     * @serial

     */

    private String baseTypeName;

    /**

     * The number of elements in this <code>SerialArray</code> object, which

     * is also the number of elements in the SQL <code>ARRAY</code> value

     * that this <code>SerialArray</code> object represents.

     * @serial

     */

    private int len;

    /**

     * Constructs a new <code>SerialArray</code> object from the given

     * <code>Array</code> object, using the given type map for the custom

     * mapping of each element when the elements are SQL UDTs.

     * <P>

     * This method does custom mapping if the array elements are a UDT

     * and the given type map has an entry for that UDT.

     * Custom mapping is recursive,

     * meaning that if, for instance, an element of an SQL structured type

     * is an SQL structured type that itself has an element that is an SQL

     * structured type, each structured type that has a custom mapping will be

     * mapped according to the given type map.

     * <P>

     * The new <code>SerialArray</code>

     * object contains the same elements as the <code>Array</code> object

     * from which it is built, except when the base type is the SQL type

     * <code>STRUCT</code>, <code>ARRAY</code>, <code>BLOB</code>,

     * <code>CLOB</code>, <code>DATALINK</code> or <code>JAVA_OBJECT</code>.

     * In this case, each element in the new

     * <code>SerialArray</code> object is the appropriate serialized form,

     * that is, a <code>SerialStruct</code>, <code>SerialArray</code>,

     * <code>SerialBlob</code>, <code>SerialClob</code>,

     * <code>SerialDatalink</code>, or <code>SerialJavaObject</code> object.

     * <P>

     * Note: (1) The <code>Array</code> object from which a <code>SerialArray</code>

     * object is created must have materialized the SQL <code>ARRAY</code> value's

     * data on the client before it is passed to the constructor.  Otherwise,

     * the new <code>SerialArray</code> object will contain no data.

     * <p>

     * Note: (2) If the <code>Array</code> contains <code>java.sql.Types.JAVA_OBJECT</code>

     * types, the <code>SerialJavaObject</code> constructor is called where checks

     * are made to ensure this object is serializable.

     * <p>

     * Note: (3) The <code>Array</code> object supplied to this constructor cannot

     * return <code>null</code> for any <code>Array.getArray()</code> methods.

     * <code>SerialArray</code> cannot serialize null array values.

     *

     *

     * @param array the <code>Array</code> object to be serialized

     * @param map a <code>java.util.Map</code> object in which

     *        each entry consists of 1) a <code>String</code> object

     *        giving the fully qualified name of a UDT (an SQL structured type or

     *        distinct type) and 2) the

     *        <code>Class</code> object for the <code>SQLData</code> implementation

     *        that defines how the UDT is to be mapped. The <i>map</i>

     *        parameter does not have any effect for <code>Blob</code>,

     *        <code>Clob</code>, <code>DATALINK</code>, or

     *        <code>JAVA_OBJECT</code> types.

     * @throws SerialException if an error occurs serializing the

     *        <code>Array</code> object

     * @throws SQLException if a database access error occurs or if the

     *        <i>array</i> or the <i>map</i> values are <code>null</code>

     */

     public SerialArray(Array array, Map<String,Class<?>> map)

         throws SerialException, SQLException

     {

        if ((array == null) || (map == null)) {

            throw new SQLException("Cannot instantiate a SerialArray " +

            "object with null parameters");

        }

        if ((elements = (Object[])array.getArray()) == null) {

             throw new SQLException("Invalid Array object. Calls to Array.getArray() " +

                 "return null value which cannot be serialized");

         }

        elements = (Object[])array.getArray(map);

        baseType = array.getBaseType();

        baseTypeName = array.getBaseTypeName();

        len = elements.length;

        switch (baseType) {

            case java.sql.Types.STRUCT:

                for (int i = 0; i < len; i++) {

                    elements[i] = new SerialStruct((Struct)elements[i], map);

                }

            break;

            case java.sql.Types.ARRAY:

                for (int i = 0; i < len; i++) {

                    elements[i] = new SerialArray((Array)elements[i], map);

                }

            break;

            case java.sql.Types.BLOB:

            for (int i = 0; i < len; i++) {

                elements[i] = new SerialBlob((Blob)elements[i]);

            }

            break;

            case java.sql.Types.CLOB:

                for (int i = 0; i < len; i++) {

                    elements[i] = new SerialClob((Clob)elements[i]);

                }

            break;

            case java.sql.Types.DATALINK:

                for (int i = 0; i < len; i++) {

                    elements[i] = new SerialDatalink((URL)elements[i]);

                }

            break;

            case java.sql.Types.JAVA_OBJECT:

                for (int i = 0; i < len; i++) {

                elements[i] = new SerialJavaObject(elements[i]);

            }

        }

  }

    /**

     * This method frees the {@code SerialArray} object and releases the

     * resources that it holds. The object is invalid once the {@code free}

     * method is called. <p> If {@code free} is called multiple times, the

     * subsequent calls to {@code free} are treated as a no-op. </P>

     *

     * @throws SQLException if an error occurs releasing the SerialArray's resources

     * @since 1.6

     */

    public void free() throws SQLException {

        if (elements != null) {

            elements = null;

            baseTypeName= null;

        }

    }

    /**

     * Constructs a new <code>SerialArray</code> object from the given

     * <code>Array</code> object.

     * <P>

     * This constructor does not do custom mapping.  If the base type of the array

     * is an SQL structured type and custom mapping is desired, the constructor

     * <code>SerialArray(Array array, Map map)</code> should be used.

     * <P>

     * The new <code>SerialArray</code>

     * object contains the same elements as the <code>Array</code> object

     * from which it is built, except when the base type is the SQL type

     * <code>BLOB</code>,

     * <code>CLOB</code>, <code>DATALINK</code> or <code>JAVA_OBJECT</code>.

     * In this case, each element in the new

     * <code>SerialArray</code> object is the appropriate serialized form,

     * that is, a <code>SerialBlob</code>, <code>SerialClob</code>,

     * <code>SerialDatalink</code>, or <code>SerialJavaObject</code> object.

     * <P>

     * Note: (1) The <code>Array</code> object from which a <code>SerialArray</code>

     * object is created must have materialized the SQL <code>ARRAY</code> value's

     * data on the client before it is passed to the constructor.  Otherwise,

     * the new <code>SerialArray</code> object will contain no data.

     * <p>

     * Note: (2) The <code>Array</code> object supplied to this constructor cannot

     * return <code>null</code> for any <code>Array.getArray()</code> methods.

     * <code>SerialArray</code> cannot serialize <code>null</code> array values.

     *

     * @param array the <code>Array</code> object to be serialized

     * @throws SerialException if an error occurs serializing the

     *     <code>Array</code> object

     * @throws SQLException if a database access error occurs or the

     *     <i>array</i> parameter is <code>null</code>.

     */

     public SerialArray(Array array) throws SerialException, SQLException {

         if (array == null) {

             throw new SQLException("Cannot instantiate a SerialArray " +

                 "object with a null Array object");

         }

         if ((elements = (Object[])array.getArray()) == null) {

             throw new SQLException("Invalid Array object. Calls to Array.getArray() " +

                 "return null value which cannot be serialized");

         }

         //elements = (Object[])array.getArray();

         baseType = array.getBaseType();

         baseTypeName = array.getBaseTypeName();

         len = elements.length;

        switch (baseType) {

        case java.sql.Types.BLOB:

            for (int i = 0; i < len; i++) {

                elements[i] = new SerialBlob((Blob)elements[i]);

            }

            break;

        case java.sql.Types.CLOB:

            for (int i = 0; i < len; i++) {

                elements[i] = new SerialClob((Clob)elements[i]);

            }

            break;

        case java.sql.Types.DATALINK:

            for (int i = 0; i < len; i++) {

                elements[i] = new SerialDatalink((URL)elements[i]);

            }

            break;

        case java.sql.Types.JAVA_OBJECT:

            for (int i = 0; i < len; i++) {

                elements[i] = new SerialJavaObject(elements[i]);

            }

            break;

        }

    }

    /**

     * Returns a new array that is a copy of this <code>SerialArray</code>

     * object.

     *

     * @return a copy of this <code>SerialArray</code> object as an

     *         <code>Object</code> in the Java programming language

     * @throws SerialException if an error occurs;

     * if {@code free} had previously been called on this object

     */

    public Object getArray() throws SerialException {

        isValid();

        Object dst = new Object[len];

        System.arraycopy((Object)elements, 0, dst, 0, len);

        return dst;

    }

    /**

     * Returns a new array that is a copy of this <code>SerialArray</code>

     * object, using the given type map for the custom

     * mapping of each element when the elements are SQL UDTs.

     * <P>

     * This method does custom mapping if the array elements are a UDT

     * and the given type map has an entry for that UDT.

     * Custom mapping is recursive,

     * meaning that if, for instance, an element of an SQL structured type

     * is an SQL structured type that itself has an element that is an SQL

     * structured type, each structured type that has a custom mapping will be

     * mapped according to the given type map.

     *

     * @param map a <code>java.util.Map</code> object in which

     *        each entry consists of 1) a <code>String</code> object

     *        giving the fully qualified name of a UDT and 2) the

     *        <code>Class</code> object for the <code>SQLData</code> implementation

     *        that defines how the UDT is to be mapped

     * @return a copy of this <code>SerialArray</code> object as an

     *         <code>Object</code> in the Java programming language

     * @throws SerialException if an error occurs;

     * if {@code free} had previously been called on this object

     */

    public Object getArray(Map<String, Class<?>> map) throws SerialException {

        isValid();

        Object dst[] = new Object[len];

        System.arraycopy((Object)elements, 0, dst, 0, len);

        return dst;

    }

    /**

     * Returns a new array that is a copy of a slice

     * of this <code>SerialArray</code> object, starting with the

     * element at the given index and containing the given number

     * of consecutive elements.

     *

     * @param index the index into this <code>SerialArray</code> object

     *              of the first element to be copied;

     *              the index of the first element is <code>0</code>

     * @param count the number of consecutive elements to be copied, starting

     *              at the given index

     * @return a copy of the designated elements in this <code>SerialArray</code>

     *         object as an <code>Object</code> in the Java programming language

     * @throws SerialException if an error occurs;

     * if {@code free} had previously been called on this object

     */

    public Object getArray(long index, int count) throws SerialException {

        isValid();

        Object dst = new Object[count];

        System.arraycopy((Object)elements, (int)index, dst, 0, count);

        return dst;

    }

    /**

     * Returns a new array that is a copy of a slice

     * of this <code>SerialArray</code> object, starting with the

     * element at the given index and containing the given number

     * of consecutive elements.

     * <P>

     * This method does custom mapping if the array elements are a UDT

     * and the given type map has an entry for that UDT.

     * Custom mapping is recursive,

     * meaning that if, for instance, an element of an SQL structured type

     * is an SQL structured type that itself has an element that is an SQL

     * structured type, each structured type that has a custom mapping will be

     * mapped according to the given type map.

     *

     * @param index the index into this <code>SerialArray</code> object

     *              of the first element to be copied; the index of the

     *              first element in the array is <code>0</code>

     * @param count the number of consecutive elements to be copied, starting

     *              at the given index

     * @param map a <code>java.util.Map</code> object in which

     *        each entry consists of 1) a <code>String</code> object

     *        giving the fully qualified name of a UDT and 2) the

     *        <code>Class</code> object for the <code>SQLData</code> implementation

     *        that defines how the UDT is to be mapped

     * @return a copy of the designated elements in this <code>SerialArray</code>

     *         object as an <code>Object</code> in the Java programming language

     * @throws SerialException if an error occurs;

     * if {@code free} had previously been called on this object

     */

    public Object getArray(long index, int count, Map<String,Class<?>> map)

        throws SerialException

    {

        isValid();

        Object dst = new Object[count];

        System.arraycopy((Object)elements, (int)index, dst, 0, count);

        return dst;

    }

    /**

     * Retrieves the SQL type of the elements in this <code>SerialArray</code>

     * object.  The <code>int</code> returned is one of the constants in the class

     * <code>java.sql.Types</code>.

     *

     * @return one of the constants in <code>java.sql.Types</code>, indicating

     *         the SQL type of the elements in this <code>SerialArray</code> object

     * @throws SerialException if an error occurs;

     * if {@code free} had previously been called on this object

     */

    public int getBaseType() throws SerialException {

        isValid();

        return baseType;

    }

    /**

     * Retrieves the DBMS-specific type name for the elements in this

     * <code>SerialArray</code> object.

     *

     * @return the SQL type name used by the DBMS for the base type of this

     *         <code>SerialArray</code> object

     * @throws SerialException if an error occurs;

     * if {@code free} had previously been called on this object

     */

    public String getBaseTypeName() throws SerialException {

        isValid();

        return baseTypeName;

    }

    /**

     * Retrieves a <code>ResultSet</code> object holding the elements of

     * the subarray that starts at

     * index <i>index</i> and contains up to <i>count</i> successive elements.

     * This method uses the connection's type map to map the elements of

     * the array if the map contains

     * an entry for the base type. Otherwise, the standard mapping is used.

     *

     * @param index the index into this <code>SerialArray</code> object

     *         of the first element to be copied; the index of the

     *         first element in the array is <code>0</code>

     * @param count the number of consecutive elements to be copied, starting

     *         at the given index

     * @return a <code>ResultSet</code> object containing the designated

     *         elements in this <code>SerialArray</code> object, with a

     *         separate row for each element

     * @throws SerialException if called with the cause set to

     *         {@code UnsupportedOperationException}

     */

    public ResultSet getResultSet(long index, int count) throws SerialException {

        SerialException se = new SerialException();

        se.initCause(new UnsupportedOperationException());

        throw  se;

    }

    /**

     *

     * Retrieves a <code>ResultSet</code> object that contains all of

     * the elements of the SQL <code>ARRAY</code>

     * value represented by this <code>SerialArray</code> object. This method uses

     * the specified map for type map customizations unless the base type of the

     * array does not match a user-defined type (UDT) in <i>map</i>, in

     * which case it uses the

     * standard mapping. This version of the method <code>getResultSet</code>

     * uses either the given type map or the standard mapping; it never uses the

     * type map associated with the connection.

     *

     * @param map a <code>java.util.Map</code> object in which

     *        each entry consists of 1) a <code>String</code> object

     *        giving the fully qualified name of a UDT and 2) the

     *        <code>Class</code> object for the <code>SQLData</code> implementation

     *        that defines how the UDT is to be mapped

     * @return a <code>ResultSet</code> object containing all of the

     *         elements in this <code>SerialArray</code> object, with a

     *         separate row for each element

     * @throws SerialException if called with the cause set to

     *         {@code UnsupportedOperationException}

     */

    public ResultSet getResultSet(Map<String, Class<?>> map)

        throws SerialException

    {

        SerialException se = new SerialException();

        se.initCause(new UnsupportedOperationException());

        throw  se;

    }

    /**

     * Retrieves a <code>ResultSet</code> object that contains all of

     * the elements in the <code>ARRAY</code> value that this

     * <code>SerialArray</code> object represents.

     * If appropriate, the elements of the array are mapped using the connection's

     * type map; otherwise, the standard mapping is used.

     *

     * @return a <code>ResultSet</code> object containing all of the

     *         elements in this <code>SerialArray</code> object, with a

     *         separate row for each element

     * @throws SerialException if called with the cause set to

     *         {@code UnsupportedOperationException}

     */

    public ResultSet getResultSet() throws SerialException {

        SerialException se = new SerialException();

        se.initCause(new UnsupportedOperationException());

        throw  se;

    }

    /**